Pedestrian tracking is a viable tool in assessing and reconstructing information on pedestrian routes. In particular, information on from where to where pedestrians walk is necessary in a lot of applications. For example, the question of assignments to target or attraction points to which pedestrians walk and identification of sources where people spawn from is of vital importance for simulators of pedestrian streams. They model the behaviour of crowds in different infrastructures and places such as buildings, stadiums, train stations, airports and the like. The behaviour of crowds is interesting for statistical and economical purposes and above all for safety reasons. The goal is to gain better control over crowd behaviour, for example, by arranging pedestrian areas in a way that pedestrian streams are controllably and predictably steered. Simulations allow running through a number of scenarios in critical situations and finding adequate measures to avoid possible dangers, like choke points, high pedestrian densities and congestions.
The validity of these simulations may be improved by feeding them data reproducing actual and real situations. Simulations usually run in finite spaces, which in turn demands information about the sources and sinks of pedestrian streams.
Data of real situations can be obtained for example by video analysis tools that track pedestrian traces automatically. These tools save time and effort in that a multitude of pedestrians can be recognized automatically and assigned respective routes over the timeframe of the tracking, thereby quickly generating routing data of pedestrians in an observed area. Several problems that arise with the application of automated tracking include the inaccessibility of certain regions within a monitored area, the distance of regions to the tracking device which renders some pedestrians unrecognizable, the appearance of obstacles in the tracking path and similar adverse conditions.
One way to link pedestrian traces to sources and or sinks is to perform a manual assignment, in many cases based on the intuition and experience of the editor. For every pedestrian trace it has to be individually decided which source and/or sink may be assigned. Naturally, such an approach is rather ineffective for large amounts of data and pedestrian traces.